1. Field of the Invention
The present invention relates to a heat developing color photosensitive material, and more particularly, to a heat developing color photosensitive material which can provide an excellent image in an extremely short developing time and which is not easily affected by variations in processing conditions.
Additionally, the present invention relates to a silver halide photographic light-sensitive material, in particular to a silver halide photographic light-sensitive material excellent in the discrimination for an image formed and raw stock storability.
2. Description of the Related Art
Formation of an image by heat development of a silver halide photographic photosensitive material is publicly known and described, for example, in "Fundamentals of Photographic Engineering (ed. by Non-Silver Salt Photography) Corona Publishing Co., Ltd.", 1982, pp. 242 to 255, U.S. Pat. No. 4,500,626 and the like.
Heat developing photographic materials using silver halide are conventionally widely used due to their excellent photographic properties such as sensitivity, (gradation and the like, as compared with the electrophotographic method, or the diazo photographic method and the like. There are several proposals regarding methods to obtain a color image by heat development using a silver halide photosensitive material, and a coloring development method, in which a dye image is formed by the coupling reaction of an oxidized compound of a developing agent with a coupler, is listed as one method thereof. Regarding the coupler and developing agent which can be used in this coloring development method, a combination of a p-phenylene diamines reducing agent with phenol or an activated methylene coupler described in U.S. Pat. No. 3,531,256, a p-amino phenol-based reducing agent described in U.S. Pat. No. 3,761,270, a combination of a sulfonamide phenol-based reducing agent with a tetravalent coupler described in U.S. Pat. No. 4,021,240, and the like are suggested.
However, this method has flaws such as the coloring of the undeveloped part of a undeveloped silver halide remaining after processing due to print out or the lapse of time, or color turbidity arising due to the existence of a color image and reduced silver on the exposed portions at the same time, and the like. To solve these flaws, a dye transferring method is proposed in which a diffusive dye is formed by heat development and transferred onto an image receiving layer.
Regarding this type of diffusion transfer type heat developing photosensitive material, there are examples where a photosensitive material and an image receiving layer which can receive a dye being supported on the same substrate, and examples where an image receiving layer is supported on a substrate other than that carrying a photosensitive material.
Particularly for heat developing color photosensitive materials, it is desirable that an image receiving material in which a dye receiving layer is supported on a substrate other than that carrying photosensitive material is used, and the dye is diffused and transferred either simultaneously with or after diffusive dye formation by color development dye to obtain a dye image having high color purity.
A method is proposed in which a diffusive dye is released or formed into an image form by heat development, and transferred onto a diffusive dye-fixing element. In this method, a negative dye image or a positive dye image can also be obtained by changing the kind of dye donative compound used or the kind of silver halide used. More details are described in U.S. Pat. Nos. 4,500,625, 4,483,914, 4,503,137, 4,559,290, Japanese Patent Application Laid-Open (JP-A) Nos. 58-149046, 60-133449, 59-218443, 61-238056, EP No. 220,746 A2, RD 87-6199, EP No. 210660 A2 and the like. However, there is the problem that since the color developed dye has been previously fixed on a dye donative material, greater light energy in the exposing light is required to lower the sensitivity of the photosensitive material, and a relatively large scale exposing light apparatus is used. Therefore, it is preferable to achieve a method in which a colorless coupler and a developing agent initially react and the desired pigment is diffused.
Regarding the above-described coupling method for forming an image, there are disclosed a color developing agent precursor which releases p-phenylenediamine, and a heat developing photosensitive material containing a coupler in Japanese Patent Application Publication (JP-B) No. 63-36487, JP-A Nos. 5-224381,6-83005 and the like, a combination of a ureido aniline-based reducing agent with an active methylene-based coupler in JP-A No. 59-111,148, and a photosensitive material using a coupler which has a polymer chain in a releasable group and releases a diffusive dye in color development in JP-A No. 58-149047.
Further, JP-A No. 9-152705 discloses a photosensitive material containing novel carbamoylhydrazine.
However, when a color developing agent or color developing agent precursor herein described is used, higher temperature developing conditions and a longer developing time are often required to obtain an image. Particularly when an image is formed under high temperature developing conditions, control of the processing machines may be difficult and a uneven image may be formed.
The photographic process, in which silver halides are used, is conventionally most widely used, since it is excellent in photographic characteristics, such as sensitivity and gradation adjustment, in comparison with another photographic process, for example, electrophotography and diazo photography. The silver halide photographic process is still vigorously investigated because the highest image quality as, in particular, color hard copies can be obtained.
In recent years, from the image-formation processing method of light-sensitive materials in which silver halides are used, a system that can give an image easily and quickly by using, for example, an instant photographic system having a built-in developing solution or a dry-process heat development processing using heating or the like, has been developed in place of the conventional wet process. With respect to heat-development light-sensitive materials, "Shashin Kogaku No Kiso (Hi-ginen Shashin-hen)", published by Corona Co., p. 242, describes them, which is only directed to the black-and-white image formation method for dry silver as a representative.
As heat-development color light-sensitive materials, recently, products called PICTROGRAPHY and PICTROSTAT (trade names) have been marketed by Fuji Photo Film Co., Ltd. This easy, quick processing method uses a redox compound having a preformed dye linked (hereinafter referred to as a coloring material), to carry out the color image formation. On the other hand, as the method for the color image formation for photographic light-sensitive materials, one in which a coupling reaction of a coupler with the oxidized product of a developing agent is used, is most popular. Many ideas on heat development color light-sensitive materials that employ that method are disclosed and filed as patent applications, for example, in U.S. Pat. No. 3,761,270, U.S. Pat. No. 4,021,240, JP-A-59-231539 ("JP-A" means unexamined published Japanese patent application) and JP-A-60-128438. Further, JP-A-9-146247, JP-A-9-146248, and JP-A-9-204031 disclose color light-sensitive materials for photographing (shooting) wherein a processing material containing a base precursor is used, and processing by heating is carried out, in the presence of a small amount of water.
In the above-described heat-development light-sensitive materials, there are points that need improving because, for example, the processing time is long, it takes time from the exposure to the output, and the processor becomes large-sized. Further, the discrimination of images needs improving.
Generally, in heat-development light-sensitive materials, the built-in reducing agent (or the developing agent) reduces the silver halide in the development processing, which is a first step to initiate an image-forming reaction. In order to quicken this, first, a method is conceivable wherein the reducing agent is made hydrophilic, to accelerate its reaction with the silver halide in the aqueous phase. However, when this method is used for usual heat-development light-sensitive materials, the reducing agent moves between layers during processing, which allows unpreferable reactions to inevitably take place, such as causing mixing of colors. In order to obviate this, a method is conceivable wherein a hydrophilic reducing agent is used as an auxiliary developing agent in combination with a lipophilic reducing agent, so that electron transfer will occur between them, thereby increasing the development rate. This idea is known in the art, and its application to heat-development light-sensitive materials is described, for example, in JP-A-1-138556.
However, generally the reducing agent increased in hydrophilicity and improved in silver developability has the problem that it is poor in stability and is easily oxidized with oxygen in the air, to be decreased, during raw stock storage. As an auxiliary developing agent particularly excellent in silver developability, a 1-phenyl-3-pyrazolidinone derivative is known in the art, but this compound is not satisfactorily stable as a built-in developing agent. The inventors of the present invention have been searching for compounds that solve these problems. It has been found under these circumstances that sulfonamidophenols, as described, for example, in U.S. Pat. No. 4,021,240, JP-A-60-128438, and JP-A-8-220717, are compounds excellent in discrimination and raw stock storability when they are built into light-sensitive materials. The performance of the sulfonamidophenols as a reducing agent has been investigated in various ways. As a result, it has been found that these compounds are compounds that have satisfactory raw stock storability, even when they are increased in hydrophilicity, as a built-in developing agent, to improve the silver developability. However, since, for the sulfonamidophenols, the oxidized product of the developing agent after the silver development is poor in stability, the oxidized product of the developing agent is hydrolyzed at the developed part, thereby producing developed silver whose quantity is more than the theoretical quantity. It has been found that, as a result, a problem arises that color contamination owing to silver images takes place.